There is a difference between a class and a training group, at least as I define it.
A class, you are not bringing much into ahead of time. You come to a class to acquire information and skills.
A training group, you bring in previous knowledge and skills. You go to a training group to 1) refine and test the skills under 2) new and unknown conditions.
My job in a class is to teach. My job in a training group is to coach and advise.